Automatic timing device



Dec. 29, 1931. F. s. SMITH 1,838,964

' AUTOMATIC TIMING DEVICE Fiied April 26, 1927 #357; M i' l 0 I 7 lmnunlgk I i0 'ymg 4 i 7 is! i (f ahum-k 1 i i l I TOR f ATTORNYEY Patented Dec. 29, 1931 UNisD STATES PATENT OFFICE FRANKLIN S. SMITH, OF BROOKLYN, NEW YORK, ASSIGNOR TO AMERICAN MACHINE FOUNDRY COMPANY, A CORPORATION F NEW JERSEY AUTOMATIC mme DEVICE Application filed April 26,

vThis invention relates to an improvement in an automatic timing device, and its underlying object is the accurate timing and discontinuation of an operation, particularly when it is to be repeated a number of times,

such or example as the operation of repeatedly photographing a negative upon a lithographie press plate, or the repeated exposure of articles to certain processes, as in heat-treating, aging, conditioning, etc;

The device herein described is arranged to indirectly stop the process or opera-tion timed by closing an electric circuit at the proper time, this circuit energizing the tripping device of a magnetic circuit-breaker, which, in turn, discontinues the process. In the case o an electrically operated process, involving exposure to light, heat, or electrochemical action, the device can be used to automatically and directly shut oli the electric supply current after the given time has .elapsed upon closing of the operating switch. Y

The device consists of a setable stationary part including a contact-maker mounted on a dial, the Contact being in closed position at zero setting oit the dial, vand of a motoroperated movable part carrying contact closing means, the driving motor being so geared that the time required by the motor-to move the contact closure through one revolution corresponds to the maximum interval to be timed. By setting the dial the contactv maker is opened andmoved away from the contact closure, and upon starting the timing motor, which is done automatically in beginning the process to be timed, it will take the contact closure exactly the time indicated by the dial setting to follow the contactmaker into contact closing position.

Thus, for a three-minute timer, the circumference of the dial is divided into 180 divisions corresponding to the number of seconds in three minutes, and the division at which the dial is set gives the exact number of seconds after which the timer acts. At the end of the timed period, the action of the timer stops the timing motor and releases a brake associated with the transmission gearing, thereby permitting a counter-weight to 1927. Serial No. 186,644.

pull the movable part back into zero position, so that the operation may be repeated as idrarliy times as desired without resetting'the In the accompanying drawings, in which like characters of reference indicate the same or like parts, Fig. 1 is a side elevation, partly in section, of a timing device constructed in accordance with the invention; Fig. 2 is a rear view of the same taken from the line 2-2 in Fig. 1; Fig. 3 is a fragmentary front view taken on the line 3-3 in Fig. l; and Fig. 4 is a diagram of the electrical connections.

In carrying the invention into effect, there is provided a graduated dial, meanswhereby said dial may be set to establish a predetermined interval for operation, a contactmakercarried by said dial, al constant speed motor, contact closing means moved by said fmotor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation. These parts may be varied in construction Within the scope of the claims, for the specic device selected to illustrate the .invention is but one of numerous possible concrete embodiments of the same. The invention therefore is not to be restricted to the precise details of the structure shown and described.

Referring to the drawings, the device is mounted on a plate 4, to which are attached posts 5, carrying a cross piece 6. To the plate 4 is fixed an axial support 7, which carries. a. fixed pointer 8 and on which the gear wheel 9 turns, a dial 10 and hub 11 carrying a. disk 12 being secured to the gear wheel 9.

The gear Wheel 9 is in mesh with, and may be rotated by, a pinion 13, mounted on a shaftv 14,A4 supported by a sleeve 15, which passes through the plate 4 and is slidable in a block 16 to an extent limited by a shoulder adjacent the plate 4. The block 16 is fastened to the plate 4;. A turning knob 17 is attached to the outer end of the shaft 14 and holds in place a. washer 18 pinned to the sleeve 15, so that a. spring 19, which bears against the plate 4 and the washer 18, pushes against the knob 17, 1W

thereby holding the shaft 14 in its outermost position, in which the web of the pinion 13 rests against the face of the block 16. By pushing the knob 17 against the plate 4, the shaft 14 is moved inwardly until the shoulder` of the sleeve 15 rests against the plate 4, in which position the pinion 13 is clear of the block 16 and can be easily turned by means of the knob 17 while inthe outer position of the knob 17, the friction between the pinion 13 and the block 16, which is due to the action of the spring 19, locks the pinion 13, so that the dial 10 will not be turned by accidentally touching the knob 17.

On the disk 12, which is made of insulating material, are mounted the current terminal studs 20 and 21, the former having a slotted end in which is inserted the resilient contact blade 22 resting in its natural position against a stop 23 carried by the disk 12. In the zero position of the disk 12, when a counter-weight 24 has pulled the spider 25, supporting a disk 26, into engagement with a stop 27 attached to one of the frame posts 5,

the contact-making blade 22 rests against a contact closure 28, attached to the disk 26, and by it is held in contact with the terminal stud 21, thereby closing the circuit 29. When the dial 10 is set in a counterclockwise direction as viewed from the front of the instrument, Fig. 3, to any desired time interval, the disk 12 is carried along with it, thereby moving the contact blade 22 away from the contact closure 28 and opening the electric circuit 29, which supplies a tripping magnet operating the main cutout. When the main circuit is closed, current is also supplied by wires 30 to the motor 31 which, through a suitable gear reduction contained in the casing 32, drives the shaft 33 connected to it by a coupling 34 in a clockwise direction as viewed from the front of theinstrument, Fig. 3. It may be here remarked that the device may be used on either alternating current supply or direct current supply, but in either case, the

motor 31 must be a constant speed motor.

For alternating current supply, therefore, a synchronous motor is used, and, for direct current supply, preferably a compoundwound motor with suitably proportioned series-winding. In case of a synchronous alternating current motor, the speed is constant as long as the frequencylofthe supply source does not vary, and the device actually counts alternations; but since, at constant frequency, each alternation represents a definite time period (1/120 second for 60-cycle current), the device practically counts time.

The motor 31 Iis supported from the cross piece 6 by means of studs 35. The forward end of the shaft 33 is journaled in a ball bearing 36, carried by a bearing holder 37, which is attached to the axial support 7. On the shaft 33 is mounted a ear 38, with which are in mesh the differentials 39, running in the internal gear 40, carried by the spider 25, turning on a ball bearing 41, placed upon the axial support 7. The differentials 39 turn on ball bearings 42, carried by shafts 43, supported between the bearing disks and 45, the former turning on the all bearing 46 on the axial support 7, and the latter on the ball bearing 47 carried by the shaft 33. Spacers 48, 49 and 50 serve to keep the ball bearings in their proper places. When the motor 3 1 is running, the disks 44 and 45 are held stationary by means of a brake 51 engaging the bearing disk 45. The brake 51 is operated by an electro-magnet 52, connected by wires 53, to the circuit supplying motor 31. The electromagnet 52 and the brake 51 are supported by a bracket 54 attached to the cross piece 6.

When the main current is broken by action of the trip magnet operated from the circuit 29, current also stops flowing in the motor 31 and the brake electro-magnet 52. At the end of the timed period, therefore, the brake 51 is automatically released and falls against the stop 55, carried by the bracket 54, permitting the counter-weight 24, which is shown as a length of chain attached to the periphery of the disk 26, to pull said disk into zero position ready for a repetition of the timing action as soon as the main circuit is again closed. In this manner, the process operating circuit can be closed any number of times 1n succession, and each time the process 1s i automatically stopped after exactly the same time interval has elapsed.

Since for maximum time interval setting of the instrument, the contact closure disk 26 must make a complete revolution, all arms of the spider 25, except the one engaging the stop 27 in the zero position of the disk 26, are provided with slots-or cutouts 56, which allow them to pass the stop 27 without engaging it.

The groove in the disk 26, instead of being circular, may be made of spiral shape, the

chain 24 being fastened at the innermost point of the groove, so that as the disk 26 turns and the chain winds up, the lever arm of the counterweight 24 becomes greater as the hanging weight reduces, thereby producing a constant pllling moment for all'positions of the disk The setting of the dial 10 against the stationary pointer 8 is observed through an opening or window 57 provided in the plate 4 for this purpose.

In Fig. 4, a diagram of the electrical connections is shown. The process operating circuit 58, the current in which is to be timed, 1s connected to the supply circuit 59, through the contacts 60 of a clrcuit breaker having a contact lever 61, to which are attached spring 62 and which has a catch 63. The latter, when the contacts 60 are closed and the springs 62 are in tension,vengages a spring-tensioned trip lever 64 controlled by llO the electro-magnet 65. The-electro-magnet is energized by shunt-current from the main supply circuit 59, one of the taps c onnecting with the circuit 29 leading to the tlming contacts of the timing device. The motor circuit 30 and the brakecircuit 53 of the timing device are connected to the process operating circuit 58. Therefore, the timing device starts running as soon as the circuit breaker is closed, and when, ater the given time interval, the timing device closes the circuit- 29, the trip magnet 65 is energized and the trip lever 6l is pulled out of engagel ment with the catch 63, thereby allowing the springs 62 to open the contacts of the circuit breaker, thus stopping the flow of current in the circuit 58. In consequence, current stops in circuitsBO and 53, so that the motor l of the timing device ceases to run, and the brake l is released, allowing the timing i return to its starting position.

Vhatis claimed is: l. An automatic timing device comprising a graduated dial, means whereby .said dial may be set/to establish a predetermined 'nterval for operation, a Contact maker carried by said dial, a constant speed motor, contactclosing means moved by said met r, a tripping device Jr'or stopping said Contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation.

2. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined interval for operation, a contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, tripping device for stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said dial setting means including a gear associated therewith, a pinion for actuating said gear, and means for holding the set dial stationary. 3. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish al predetermined interval for operation, a Contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said Contact closing means to zero position for another operation, said dia-l setting means including a gear." associated therewith, a pinion for actuating said gear, and a spring-pressed knob for actuating said pinion and for frictionallythoiding the set dial stationary.

4. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined interval for operation, a contact maker carried by said dial, a constant speed motor, Contact closing means moved by said motor, a tripping device or stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said contact maker including a disc of insulating ma terial secured to said dial, current terminal studs secured to said disc, and a resilient contact blade supported by one of said studs and adapted to contact with the other when engaged by said Contact closing means.

5. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined iuterval for operation, a contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, a trip- 8. in automatictiming device comprising a graduated dial, means whereby said dial may be set to establish a predetermined interval for operation, a contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said contact closing means including a disc rotated by said motor and a contact closer carried by said disc and adapted to engage said contact maker.

7. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined intervai for operation, a contact maker carried by said dial, a constant speed motor, Contact closing means moved by said motor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said contact closing means including a disc rotated by said motor, reduction gearing between said disc and said motor, and a stud carried by said disc and adapted to engage said contact mal er.

8. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined interval ter operation, a contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said triping device including a spring tensioned trip ever, a circuit breaker restrained by saidl lever, and an electromagnet actuating said lever at the end of said interval.

9. An automatic timing device comprisin a graduated dial, means whereby said dia may be set to establish a predetermined interval for operation, a contact maker carried by said dial, a constant speed motor, contact closing means moved by said motor, a tripping device for'stopping said contact closing means at the end of said interval, and means for returning said contact closing means to zero position for another operation, said returning means including a Weight attached to said Contact closing means.

10. An automatic timing device comprising a graduated dial, means whereby said dial may be set to establish a predetermined interval for operation, a contact maker carried by said dial, a constant speed'motor, contact closing means moved by saidv motor, a tripping device for stopping said contact closing means at the end of said interval, and means for returning said Contact closing means to zero position for another operation, said contact closing means including a disc rotated by said motor, and 'said returning means including a chain attached to the periphery of said disc. v

11. A dial setting device for automatic timing devices, comprising a timing dial, a gear carried by said dial, a pinion for actuating said gear, and a spring-pressed knob for actuating said pinion and releasable means associated with said knob 'for frictionally holding the set dial stationary.

12. A contact maker for automatic timing devices, comprising an annular adjustable disc of insulating material, a setable timing dial secured to said disc, current terminal studs secured to said disc, and a resilient contact blade supported by one of said studs and adapted to contact with the other when engaged by contact closing means.

13. A contact maker for automatic timing devices, comprising an annular adjustable disc of insulating material, a setable timing dial secured to said disc, current terminal studs secured to said disc, a resilient contact blade supported by one of said studs, and a stud carried by said disc and against which said blade rests when not engaged by a contact closing means.

14. An automatic timing device comprising a dial, means whereby said dial may be set to establish a predetermined interval of operation, a contact maker connected to said dial, a motor, contact closing means moved by said motor, and means for returning said contact closing means to Zero position for aonther operation, said contact maker including a disc of insulating material, current terminal studs secured to said disc, and a resilient contact blade supported by one of said studs and adapted to Contact with the other When engaged by said contact closing means.

15. An automatic timing device comprising a dial, means whereby said dial may be set to establish a predetermined interval of operation, a contact maker connected to said dial, a motor, contact closing means moved by said motor to engage said contact maker at the end of the predetermined interval of operation, and means :for returning said contact closing means to Zero position for another operation.

16. An automatic timing device comprising a dial, means whereby said dial may be set to establish a predetermined interval of operation, a contact maker connected to Said dial, contact closing means, and means for returning said contact closing means to zero position for another operation, said contact closing means including a rotatable disc and a contact closer carried by said disc and adapted to engage said contact maker.

In testimony whereof, I have signed my name to this speciiication.

' FRANKLIN S. SMITH. 

